How to Kill Mint & Replant Vegetables

You must glean all rhizomes from the soil to eradicate mint.

Mint (Mentha spp.) makes a delightful addition to a garden because it emits a pleasing fragrance and repels insects. Mint grows as a perennial in U.S. Department of Agriculture plant hardiness zones 4 through 11. Once planted, rhizomatous mint spreads quickly and can take over an entire garden space if left unchecked. If you decide you would rather plant vegetables in your mint garden, you must first eliminate all the mint and prevent it from returning. You can move some mint to a new space or grow it in containers around the vegetable garden to repel insects.

1

Water the mint deeply the night before removal so the ground is evenly moist, but not wet.

2

Rake away any leaves, mulch or other debris around the perimeter of the visible mint patch and look for signs of new sprouts. Dig into the soil a bit to look for any fleshy rhizomes; mint roots have a minty scent even if foliage is not visible. If desired, you can spray the ground to mark the perimeter of the root spread so you don't miss any roots.

3

Dig up the mint plants, including as much off the roots as possible. Use a spade shovel for large plots of mint or a small garden fork for smaller patches. Push the shade or fork into the ground at one corner of the mint patch and peel back the plants in strips, if possible, to reduce the amount of digging required. Mint has relatively shallow roots, so you won't need to dig more than a few inches deep to remove the mint.

4

Shake the clumps of mint to remove dirt, while keeping the roots intact. You may find it helpful to shake the plants over a piece of wire mesh screen, which will catch any falling roots, while allowing the soil particles to fall through to the ground.

5

Spread the mint plants out on a flat surface, such as a patio or tarp, in full sun until the mint plants dry up and die completely. Add the dead mint to your compost pile to be converted into rich compost for your garden. However, if you don't let the mint dry and die completely before adding to the compost pile, the mint can take root in the compost. Alternatively, you can discard the mint in your weekly trash immediately after removal.

6

Pick through the soil and pick up any mint rhizomes that remain in the soil. You can do this by hand in a small plot, but in larger plots it is much more practical to use a rake to gather the roots into a pile, even if it means removing some soil in the process. Smooth out the soil using the back side of a bow rake when you have removed all visible rhizomes.

7

Leave the soil bare and unplanted for at least one month. Pull up any mint or other weeds that sprout during this time. Dig through the soil in the immediate area after removing new mint plants and remove any remaining rhizomes.

8

Add more topsoil to the planting area or blend organic humus materials, such as compost, manure, sphagnum peat and leaf mold, into the native soil to replenish any soil removed while removing the mint. Even after shaking the plants to release soil from the roots, you may still remove a substantial amount of soil from the planting area. The soil level in the vegetable planting space should be even with the surrounding soil level. Use a shovel or rototiller to blend the new topsoil or humus materials with the existing soil.

9

Plant the desired vegetables in the plot after one month, using the recommended spacing for each plant type. In this case, it is better to plant seedlings rather than vegetable seeds so you don't mistake emerging seedlings of desired vegetables with undesired mint and weed seedlings.

10

Add a 3- to 4-inch layer of organic mulch, such as shredded bark mulch, around the vegetable plants to suppress the growth of any mint rhizomes that may still remain active in the soil. Keep a 3-inch area around all plant stems free of mulch to avoid the risk of rot and infestation.

11

Check the vegetable garden periodically for any new mint growth and pull the plants up by the roots immediately. Pull the mulch layer back to reveal the soil so you can see the roots, ensuring removal of all rhizomes.

Things You Will Need

Leaf rake

Shovel

Landscaping spray paint

Spade

Garden fork

Wire mesh screen (optional)

Tarp (optional)

Bow rake

Topsoil or humus materials

Rototiller (optional)

Vegetable seedlings

Shredded bark mulch

Tip

An herbicide spray over the bare soil may sound like a simple solution over waiting one month and tediously removing emerging mint plants, but you don't want to take a risk that the herbicide could damage your vegetables.

Another option is to mow the mint and cover the area with a layer of newspaper four layers thick. The newspaper will smother the roots and eventually kill the mint, but this takes a full growing season to ensure success. While digging takes more work, you can kill all the mint and plant your vegetable garden in the same growing season.

Spearmint (M. spicata) and peppermint (M. piperita), grown in zones 5 through 9, are among the most common mint species.

About the Author

A former cake decorator and competitive horticulturist, Amelia Allonsy is most at home in the kitchen or with her hands in the dirt. She received her Bachelor's degree from West Virginia University. Her work has been published in the San Francisco Chronicle and on other websites.